Wonderful story. The dialogue is one of the best things about it, but the characterizations are also excellent. You've got quite an intriguing mystery going as well, in which you control perspective and limited point of view in a masterful way. Readers know more than Lois but we still don't know everything, which makes the story even more engrossing.
All along I've been a bit frustrated at how blind Lois seems to be, although in fairness you've written the perspective so well that it's impossible to blame her for not seeing the truth. Every time they run into Superman I do keep hoping that she'll realize something about him is wrong, and that he is *not* the real Superman. She should be intuitive about Superman as well as about Clark.
In fact, I was sort of hoping Lois would eventually figure everything out on her own, though, so I will probably be disappointed if it turns out that she just read a letter that Clark had written explaining everything, and chickened out of giving to her. That makes her investigative skills more akin to putting together a jigsaw puzzle, and plus I love the psychological dimension of revelation stories.
Anyway, I am sure you will come up with something much more original than that.
